Japanese Prime Minister Shinzo Abe called the launch "absolutely intolerable".
South Korea has condemned the actions of their neighbour North Korea who fired a ballistic missile which traveled nearly 500 kilometres towards the Sea of Japan.
The missile - launched at around 7.55am local time from Banghyon air base in the western province of North Pyongan Province - flew about 310 miles east towards the Sea of Japan before it dropped into water, according to the South Korean defence ministry.
In a statement South Korea's defence ministry said "It is believed that today's missile launch... is aimed at drawing global attention to the North by boasting its nuclear and missile capabilities.
"It is also believed that it was an armed provocation to test the response from the new US administration under President Trump."
The South Korean military said it suspected the North might have been testing a intermediate-range Musudan missile.
Last October, North Korea test-fired Musudan missiles twice from the same air base. The North has conducted two nuclear tests and a number of missile-related tests at an unprecedented rate since early last year.
Kim Jong-Un said in his New Year speech that the country was close to test-launching an intercontinental ballistic missile (ICBM) and state media said such a launch could come at any time.
Japanese Prime Minister Shinzo Abe has also denounced the launch saying it is "absolutely intolerable".
President Trump said at a news conference with Abe that "I just want everybody to understand, and fully know, that the United States of America is behind Japan, our great ally, 100%."
It is the first time the isolated state of North Korea has tested such a device since Mr Trump took office.
The Pentagon said the projectile was a medium- or intermediate-range ballistic missile. The launch never posed a threat to North America, it added, but did not state whether it believed the launch had been a success or failure.